Wurlitzer 7300, Service Instructions Manual

Page 1: ...MODEL 7300 ORGAN SERVICE INSTRUCTIONS and PARTS CATALOG PART No 131512 THE WURLITZER CO ELKHART IND T I I t I ...

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Page 3: ...COMBO ORGAN Com i lr z Tran 13053 ...

Page 4: ...Cable 12 lg 130577 6 lg 130578 EXPRESSION PEDAL 130558 Complete Rubber Bumper 130526 ...

Page 5: ...AC Cord 130670 Complete M 7300 COMBO ORGAN Bottom Bumpers 130567 Top Screws 76649 12 Washers 15092 1 End Caps 130590 Name Plate 130713 ...

Page 6: ... just IC s The total range of the audio frequencies handled by the generators is approximately 65 Hz to 8 000 Hz There are two printed circuit boards used One board covers notes from C to F and the other F to B The physical layout of a typical board is shown on drawing No 130677 Both of these printed board circuits are identical Each board contains the same number of discrete components and IC s F...

Page 7: ...or example the first group of note signals are C to G 9 notes The remaining five groups are 8 notes in length Therefore at position S on the keyboard whenever the first nine keys are depres sed 16 signals will appear on the black wire 8 signals on the purple wire 4 signals on the red wire The pitch of these signals is shown in the chart below the keyboard The other group divisions for the rest of ...

Page 8: ...a common lead is then wired to the three Stop Switches String Bass and Reed The sound level of these three stops can be set by the solo switch This switch controls a 39 K re sistor 3 across the normal 470 K 2 feedback resistor in the collector base circuit of stage TR 1 With the 39 K 3 resistor across the 470 K 2 greater feedback is provided to lower the level of this stage When the 39 K 3 is remo...

Page 9: ...he Combo Organ A step down power transformer having two isolated secondary windings is used Silicon diodes are used in a conventional rectifier configuration The low voltage section taken out of diodes D 1 and D 2 is filtered to ground by a large 10 000 mfd capacitor 241 The DC output is then fed to two transistors TR 16 and TR 12 to provide extremely good 3 45 Volts DC regulation This regulated v...

Page 10: ...re to lay the assembly on a pad 3 Using a soft brush and denatured alcohol the springs and bus bars can be cleaned Be careful not to catch any of the contact springs in the brush EXPRESSION PEDAL The 10 K control found inside of the housing of the Expression Pedal can be changed as follows 1 Turn the pedal over and remove the cover plate 2 The socket head set screw holding the shaft and arm is a N...

Page 11: ...ve been adjusted the entire organ is tuned because these twelve master top octave notes control the entire range of the organ no matter what stop is used ELECTRONIC UNITS Important Before replacing electronic components indiscriminately the technician should always perform a visual check looking for broken wires cold solder joints etc One of two types of meters are to be used in troubleshooting th...

Page 12: ...nted Circuit Board 3 Check 1 mfd 110 Capacitor 4 Check Lever Switch 1 Check TR 6 Stage 2 Check J 2 JumP er 3 Check 47 mfd 97 Capacitor 4 Check Lever Switch 1 Check TR 5 Stage 2 Check J 1 Jumper 3 Check 22 mfd 88 Capacitor 4 Check Lever Switch 1 Check TR 4 2 Check 15 mfd 87 Capacitor 3 Check 3 3 K 86 Resistor 4 Check Lever Switch 1 Check wire connections from group signal take off points shown on S...

Page 13: ...Check Reed Stop Switch 2 Check components numbered 62 63 64 65 R Vibrato dead l Check TR 14 Stage 2 Check TR 13 Stage 3 Check Vibrato Switch 4 Check wire from Vibrato Switch to Generators s All keys sound electri l Check 75 V supply to signal cally noisy on all buss rods of keyboard All stops buss rods should measure 75 V when no keys depressed 2 Check 175 mfd 15 Capacitor in Power Supply ...

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Page 15: ... F I C AT I O N O N S C H E M AT I C N O 1 3 0 7 1 6 3 S E E P R I N T ED B OA R D A S S E M B LY 8 N O 1 3 0 69 6 F O R I T E M S 2 2 3 2 3 1 4 S E E P RI N T E D BOA R D A S S E M B LY 4 N O 1 3 0 68 1 FO R I T E M S 2 1 4 2 2 2 T H E W U R L I T Z E R CO E L KHART D IVISIO N ELKHART I N D I A N A M OD E L 730 0 C O M BO O R G A N T I T L E F I LT E R BOA R D STA RT I N G S E R I A L N O E 200 0...

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Page 17: ... C B A V N O T E S BOARD ASSEMBLIE S U S E D C T O F AND F T O B 0 _ 1 3 0 5 3 9 I _ C 4 1 3 0 5 3 9 c s I __ 3 C 5 3 9 I _ L G 0 2 S E E S C H E MAT IC 1 3 0 6 8 4 FOR CON N ECT IONS A N D CO M P LETE C I R C U I T S 3 N U M B E R S O N C O M P O N E N T S C O R R E S PO N D TO NUM B E R S O N S C H EMAT I C 1 3 0 6 8 4 4 DOT O N J C I N D I C AT E S PO S I T I O N OF P I N N O I T H E W U R L I ...

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Page 19: ... 100V Capacitor 056 MFD lO0V Capacitor 047 MFD 100V Capacitor 039 MFD 100V Capacitor 033 MFD lO0V Capacitor 027 MFD lO0V Capacitor 022 MFD l00V Capacitor 018 MFD lO0V Capacitor 015 MFD lO0V Capacitor 012 MFD l O0V Capacitor 01 MFD lO0V Capacitor 0068 MFD lOOV Capacitor 0056 MFD lO0V Capacitor 0047 MFD DISC Capacitor 0033 MFD DISC Capacitor 0018 MFD DISC Capacitor 001 MFD DISC Capacitor 820 MMFD DI...

Page 20: ...30509 130597 130598 130599 Escutcheon Casting Switch Brkt Wire Assembly Button Mtg Pl Switch Assembly Switch ON OFF Control Neon Glow Lamp Speed Nut Sleeving Switch M tg Brkt Assembly Switch Switch EXPRESSION PEDAL ASSEMBLY COMPLETE 13055 8 130572 1305 26 1305 22 Felt Pad Rubber Bum per Rubber Pad LEG ASSEMBLY COMPLETE 130560 130705 130706 Thum b Screw Special Nut ...

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